1. Field of the Invention
The present invention relates to a surface treatment apparatus which can efficiently form fine depressions and protrusions in any sheet selected from among an inkjet sheet, thermosensitive recording sheet, heat-developing sheet, electrophotographic sheet and silver halide photographic sheet, and to an image-forming apparatus comprising this surface treatment apparatus.
2. Description of the Related Art
In the past, images have been formed by various methods such as silver halide photography, heat developing, inkjet recording, thermosensitive recording and electrophotography. In the prior art, techniques for controlling the gloss of image prints obtained by these various methods were not well-known.
However, Japanese Patent Application Laid-Open (JP-A) No. 05-053288 discloses a photographic apparatus which, in addition to a processor part which produces a printed photograph by developing a printing paper which has been bake-exposed, also comprises a drying part and surface texture treatment part to finish the printed photograph. The surface texture treatment part of this photographic apparatus comprises a pressure roller having surface depressions and protrusions which forms a predetermined surface texture on the printed photograph surface, and a shift mechanism which sets this pressure roller in a state where it can be pressed against the printed photograph. As a result, printed photographs having a desired surface texture can easily be obtained without replacing printing papers or interrupting the bake-exposure.
However, the surface texture treatment part in this photographic apparatus described in the aforesaid JP-A No. 05-053288 had a construction wherein the printed photograph surface was pressed by a pressure roller having a desired transfer roughness, and the depressions and protrusions on the pressure roller surface were transferred to the printed photograph. The surface texture treatment part of this photographic apparatus was adapted for use only with silver halide photographic sheets. Also, to obtain particular surface textures, it was necessary to provide a number of rollers having surface roughness for each texture, so in practice only about 1 to 3 surface textures could be realized. Therefore, according to JP-A No. 05-053288, only one type of treatment could be performed, there was no systematic generality, and performance was unsatisfactory from the viewpoints of working efficiency and energy efficiency.
In JP-A No. 2001-053943, an image-forming system was proposed wherein color information and gloss information are acquired from an image, and image recording is performed on a recording medium based on these two types of image information. Image recording is performed by converting gloss information or non-gloss information into the thermal energy of a thermosensitive head.
In the aforesaid JP-A No. 05-053288 and JP-A No. 2001-053943, surface treatment is performed by applying heat and pressure to an image-forming layer, but there is no mention of the surface treatment of the thermoplastic resin layer, and even if the surface of the image-forming layer alone is treated, the depression and protrusion pattern formed on the surface (interface) of the thermoplastic resin layer underneath has an effect on the image-forming surface due to time-dependent variation, so a desired depression and protrusion pattern cannot be obtained.
Moreover, if a contact member is released from the sheet at high temperature, the depression and protrusion pattern on the contact member transferred to the thermoplastic resin layer and image-forming layer sometimes produced an undesirable plastic deformation due to external factors. Moreover, if a surface coating layer (transparent clear layer) is provided to improve the gloss as described in the aforesaid JP-A No. 2001-053943, it led to higher costs.
It is therefore an object of the present invention to provide a surface treatment apparatus which can efficiently form fine depressions and protrusions in any sheet selected from among an inkjet sheet, thermosensitive recording sheet, heat-developing sheet, electrophotographic sheet and silver halide photographic sheet, and to an image-forming apparatus comprising this surface treatment.